Monaghan Castle is a historic structure located in County Monaghan, Ireland. Built in the 16th century, it served as a stronghold for the O'Neill clan, who were prominent in the region. The castle features a distinctive round tower and remnants of its defensive walls, showcasing the architectural style of its time. Today, the castle is a popular tourist attraction, offering visitors a glimpse into Ireland's medieval past. Although much of the structure is in ruins, it remains an important symbol of the area's history and heritage, drawing history enthusiasts and locals alike.